"Natural family planning" : effective birth control supported by the catholic church.

During 20-22 September Manchester is to host the 1993 follow up to last year's « earth suit » in Rio de Janeiro.

At that summit the threat posed by world overpopulation received considerable attention.

Catholicism was perceived as opposed to birth control and therefore as a particular threat.

This was based on the notion that the only method of birth control approved by the church-natural family planning-is unreliable, unacceptable, and ineffective.

In the 20 years since E L Billings and colleagues first described the cervical mucus symptoms associated with ovulation natural family planning has incorporated these symptoms and advanced considerably.